No, glaciers are not pure water, although they are made from freshwater.
The Composition of Glaciers
Glaciers are formed from accumulated snowfall. Snow, being frozen rainwater, is essentially freshwater. The process of evaporation that leads to snowfall leaves behind the heavier salt molecules from ocean water. Therefore, the initial snow forming the glacier is freshwater.
However, while the source water is freshwater, glaciers themselves aren't completely pure. They contain:
- Dissolved Minerals: As the glacier moves, it interacts with rocks and soil, picking up small amounts of dissolved minerals and sediments. This is particularly true as the ice melts.
- Air Bubbles: Glacial ice traps air bubbles within its structure, representing the atmosphere at the time the snow fell. These bubbles aren't exactly "impurities," but they're not pure water either.
- Suspended Particles: Dust, pollen, and other airborne particles can become incorporated into the snow and ice.
- Debris: Rocks, pebbles, and other debris can be picked up and transported within the glacier. These can form moraines when the ice melts.
Therefore, while glaciers originate from freshwater snowfall, they aren't solely composed of pure H₂O. They contain trace amounts of various other substances picked up throughout their formation and movement.
